The forging apparatus of gear and the forging method of gear

摘要

PROBLEM TO BE SOLVED: To provide a forging device of a gear and a forging method of the gear, being simple in a structure, by easily forming the gear with crowning by cold forging.SOLUTION: A forging device A of a gear for molding in a helical gear 10 with crowning by cold-forging a second cylindrical gear 10c for forming a tooth 12b on an outer peripheral surface, is provided with a counter punch 22, a die 25, a die holder 27 and a die punch 37. The counter punch 22 is constituted for forming a swelling part 23 on the outer peripheral surface of a tip part 22c of a body, and the die 25 forms a tooth-shape molding tooth 25a for forming a tooth 12 of the helical gear 10 on an inner peripheral surface by being installed at an interval on the outer peripheral side of the swelling part 23. The die holder 27 is arranged on the outer peripheral side of the die 25, and when the die punch 37 presses the die 25 to the inner side of the die holder 27, the die 25 is deformed in the diametrical contraction direction.SELECTED DRAWING: Figure 4